vmm: enable coredump

Based on the newly added guest_debug feature, this patch adds http
endpoint support.

Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Co-authored-by: Sebastien Boeuf <sebastien.boeuf@intel.com>

Cargo.toml

@@ -58,6 +58,7 @@ amx = ["vmm/amx"]
 cmos = ["vmm/cmos"]
 fwdebug = ["vmm/fwdebug"]
 gdb = ["vmm/gdb"]
+guest_debug = ["vmm/guest_debug"]
 kvm = ["vmm/kvm"]
 mshv = ["vmm/mshv"]
 tdx = ["vmm/tdx"]

vmm/src/api/http.rs

@@ -161,6 +161,8 @@ lazy_static! {
         r.routes.insert(endpoint!("/vm.send-migration"), Box::new(VmActionHandler::new(VmAction::SendMigration(Arc::default()))));
         r.routes.insert(endpoint!("/vm.shutdown"), Box::new(VmActionHandler::new(VmAction::Shutdown)));
         r.routes.insert(endpoint!("/vm.snapshot"), Box::new(VmActionHandler::new(VmAction::Snapshot(Arc::default()))));
+        #[cfg(feature = "guest_debug")]
+        r.routes.insert(endpoint!("/vm.coredump"), Box::new(VmActionHandler::new(VmAction::Coredump(Arc::default()))));
         r.routes.insert(endpoint!("/vmm.ping"), Box::new(VmmPing {}));
         r.routes.insert(endpoint!("/vmm.shutdown"), Box::new(VmmShutdown {}));
 

vmm/src/api/http_endpoint.rs

@@ -4,6 +4,8 @@
 //
 
 use crate::api::http::{error_response, EndpointHandler, HttpError};
+#[cfg(feature = "guest_debug")]
+use crate::api::vm_coredump;
 use crate::api::{
     vm_add_device, vm_add_disk, vm_add_fs, vm_add_net, vm_add_pmem, vm_add_user_device,
     vm_add_vdpa, vm_add_vsock, vm_boot, vm_counters, vm_create, vm_delete, vm_info, vm_pause,
@@ -151,6 +153,12 @@ impl EndpointHandler for VmActionHandler {
                     api_sender,
                     Arc::new(serde_json::from_slice(body.raw())?),
                 ),
+                #[cfg(feature = "guest_debug")]
+                Coredump(_) => vm_coredump(
+                    api_notifier,
+                    api_sender,
+                    Arc::new(serde_json::from_slice(body.raw())?),
+                ),
                 ReceiveMigration(_) => vm_receive_migration(
                     api_notifier,
                     api_sender,

vmm/src/api/mod.rs

@@ -99,6 +99,9 @@ pub enum ApiError {
     /// The VM could not restored.
     VmRestore(VmError),
 
+    /// The VM could not be coredumped.
+    VmCoredump(VmError),
+
     /// The VMM could not shutdown.
     VmmShutdown(VmError),
 
@@ -189,6 +192,12 @@ pub struct VmSnapshotConfig {
     pub destination_url: String,
 }
 
+#[derive(Clone, Deserialize, Serialize, Default, Debug)]
+pub struct VmCoredumpData {
+    /// The coredump destination file
+    pub destination_url: String,
+}
+
 #[derive(Clone, Deserialize, Serialize, Default, Debug)]
 pub struct VmReceiveMigrationData {
     /// URL for the reception of migration state
@@ -310,6 +319,10 @@ pub enum ApiRequest {
     /// Restore from a VM snapshot
     VmRestore(Arc<RestoreConfig>, Sender<ApiResponse>),
 
+    /// Take a VM coredump
+    #[cfg(feature = "guest_debug")]
+    VmCoredump(Arc<VmCoredumpData>, Sender<ApiResponse>),
+
     /// Incoming migration
     VmReceiveMigration(Arc<VmReceiveMigrationData>, Sender<ApiResponse>),
 
@@ -402,6 +415,10 @@ pub enum VmAction {
     /// Snapshot VM
     Snapshot(Arc<VmSnapshotConfig>),
 
+    /// Coredump VM
+    #[cfg(feature = "guest_debug")]
+    Coredump(Arc<VmCoredumpData>),
+
     /// Incoming migration
     ReceiveMigration(Arc<VmReceiveMigrationData>),
 
@@ -441,6 +458,8 @@ fn vm_action(
         ResizeZone(v) => ApiRequest::VmResizeZone(v, response_sender),
         Restore(v) => ApiRequest::VmRestore(v, response_sender),
         Snapshot(v) => ApiRequest::VmSnapshot(v, response_sender),
+        #[cfg(feature = "guest_debug")]
+        Coredump(v) => ApiRequest::VmCoredump(v, response_sender),
         ReceiveMigration(v) => ApiRequest::VmReceiveMigration(v, response_sender),
         SendMigration(v) => ApiRequest::VmSendMigration(v, response_sender),
         PowerButton => ApiRequest::VmPowerButton(response_sender),
@@ -526,6 +545,15 @@ pub fn vm_restore(
     vm_action(api_evt, api_sender, VmAction::Restore(data))
 }
 
+#[cfg(feature = "guest_debug")]
+pub fn vm_coredump(
+    api_evt: EventFd,
+    api_sender: Sender<ApiRequest>,
+    data: Arc<VmCoredumpData>,
+) -> ApiResult<Option<Body>> {
+    vm_action(api_evt, api_sender, VmAction::Coredump(data))
+}
+
 pub fn vm_info(api_evt: EventFd, api_sender: Sender<ApiRequest>) -> ApiResult<VmInfo> {
     let (response_sender, response_receiver) = channel();
 

vmm/src/coredump.rs

@@ -79,7 +79,6 @@ pub struct X86_64UserRegs {
 unsafe impl ByteValued for X86_64UserRegs {}
 
 #[repr(C)]
-#[allow(dead_code)]
 pub struct X86_64ElfPrStatus {
     pub pad1: [u8; 32],
     pub pid: u32,

vmm/src/lib.rs

@@ -18,6 +18,8 @@ use crate::config::{
     add_to_config, DeviceConfig, DiskConfig, FsConfig, NetConfig, PmemConfig, RestoreConfig,
     UserDeviceConfig, VdpaConfig, VmConfig, VsockConfig,
 };
+#[cfg(feature = "guest_debug")]
+use crate::coredump::GuestDebuggable;
 #[cfg(all(feature = "kvm", target_arch = "x86_64"))]
 use crate::migration::get_vm_snapshot;
 use crate::migration::{recv_vm_config, recv_vm_state};
@@ -562,6 +564,15 @@ impl Vmm {
         }
     }
 
+    #[cfg(feature = "guest_debug")]
+    fn vm_coredump(&mut self, destination_url: &str) -> result::Result<(), VmError> {
+        if let Some(ref mut vm) = self.vm {
+            vm.coredump(destination_url).map_err(VmError::Coredump)
+        } else {
+            Err(VmError::VmNotRunning)
+        }
+    }
+
     fn vm_shutdown(&mut self) -> result::Result<(), VmError> {
         if let Some(ref mut vm) = self.vm.take() {
             vm.shutdown()
@@ -1684,6 +1695,15 @@ impl Vmm {
 
                                 sender.send(response).map_err(Error::ApiResponseSend)?;
                             }
+                            #[cfg(feature = "guest_debug")]
+                            ApiRequest::VmCoredump(coredump_data, sender) => {
+                                let response = self
+                                    .vm_coredump(&coredump_data.destination_url)
+                                    .map_err(ApiError::VmCoredump)
+                                    .map(|_| ApiResponsePayload::Empty);
+
+                                sender.send(response).map_err(Error::ApiResponseSend)?;
+                            }
                             ApiRequest::VmmShutdown(sender) => {
                                 let response = self
                                     .vmm_shutdown()